Rebind window surface fbo after native GL rendering

If the user called QGLFramebufferObject::bind()/release() during a
beginNativePainting() callout, the release() would reset the context's
fbo to zero, not the actual window surface fbo.

Task-number: QTBUG-6204
Reviewed-by: Tom

1 files changed, 10 insertions, 0 deletions

diff --git a/src/opengl/qglpaintdevice.cpp b/src/opengl/qglpaintdevice.cpp
index 2867de5..bcd90a5 100644
--- a/src/opengl/qglpaintdevice.cpp
+++ b/src/opengl/qglpaintdevice.cpp
@@ -89,6 +89,12 @@ void QGLPaintDevice::beginPaint()
         ctx->d_ptr->current_fbo = m_thisFBO;
         glBindFramebuffer(GL_FRAMEBUFFER_EXT, m_thisFBO);
     }
+
+    // Set the default fbo for the context to m_thisFBO so that
+    // if some raw GL code between beginNativePainting() and
+    // endNativePainting() calls QGLFramebufferObject::release(),
+    // painting will revert to the window surface's fbo.
+    ctx->d_ptr->default_fbo = m_thisFBO;
 }
 
 void QGLPaintDevice::ensureActiveTarget()
@@ -101,6 +107,8 @@ void QGLPaintDevice::ensureActiveTarget()
         ctx->d_ptr->current_fbo = m_thisFBO;
         glBindFramebuffer(GL_FRAMEBUFFER_EXT, m_thisFBO);
     }
+
+    ctx->d_ptr->default_fbo = m_thisFBO;
 }
 
 void QGLPaintDevice::endPaint()
@@ -111,6 +119,8 @@ void QGLPaintDevice::endPaint()
         ctx->d_ptr->current_fbo = m_previousFBO;
         glBindFramebuffer(GL_FRAMEBUFFER_EXT, m_previousFBO);
     }
+
+    ctx->d_ptr->default_fbo = 0;
 }
 
 QGLFormat QGLPaintDevice::format() const